阅读下面短文，根据文章的内容选择最佳答案。

1. Kids should send their pictures _____.

    A. to 15 Barrett Road

    B. to 12 High Street

    C. before September 10

2. In Tony's Shop, you can buy _____.

    A. chocolate    

    B. magazines

    C. pictures

3. The ticket will cost you _____.

    A. $9

    B. $7

    C. $35

4. The theater advises people to buy tickets _____ .

    A. on the Internet

    B. by telephone

    C. from friends

螺旋角ω是麻花钻钻头轴线和刃带切线之间的夹角。ω越大，切削越容易，但强度（）。